in English, Portuguese A cirurgia paraendodôntica é um procedimento que visa resolver problemas que não poderiam ser resolvidos, ou quando não é possível realizar o tratamento endodôntico convencional. O objetivo deste estudo experimental foi comparar a microinfiltração apical de dentes seccionados a 45° ou 90° em relação ao longo eixo do dente e extremidade radicular preenchida com agregado de trióxido mineral (MTA) utilizando estereomicroscopia. Neste estudo, 26 incisivos centrais superiores foram utilizados. Limpeza e modelagem foram realizadas com o uso da técnica de Oregon e as amostras foram divididas aleatoriamente em dois grupos. No Grupo A (n = 10) foi realizada seção apical em ângulo de 90°, reali zando retrocavidade com ponta ultrassônica e retrobturação com MTA. No grupo B (n = 10), os mesmos procedimentos foram realizados, mas a seção apical estava em um ângulo de 45°. Em seguida, as amostras foram imersas em um corante (nanquim), colocadas em estufa a 37°C por 48 h, antes da aplicação da técnica de clareamento. Posteriormente, os dentes foram avaliados por estereomicroscópio, com aumento de 20x, para análise do vazamento de corante. Os dados foram submetidos ao teste t de Student, com nível de significância p less then 0,05. Houve diferença estatisticamente significante entre os grupos. O grupo B apresentou maiores valores de microinfil tração apical em comparação ao grupo A (P = 0,004), mas ambos os grupos apresentaram vazamento de corante. Os resultados mostraram que a seção apical de 90° promoveu menores valores de microinfiltração de corante na interface do material retrobturador dentinário do que a seção 45° e pode ser considerada a técnica mais efetiva para preparo apical em cirurgia paraendodôntica.Chirality is ubiquitous in nature and plays mysterious and essential roles in maintaining key biological and physiological processes. As biological systems display high selectivity for chiral biomolecules, chiral bio-nanoscience has become a popular research field during the last decade. Homochirality, as an essential attribute of natural compounds (l-amino acids, d-sugars, etc.), inspired the emergence of synthetic chiral nanomaterials, which in turn impacted their biological functions and fates. This review is a comprehensive overview of the interactions between chiral inorganic nanostructures and biosystems. We start with the recent progress in biocompatible chiral nanomaterials and focus on stereospecific biological interactions ranging from enantioselective reactions in applications such as sensing and catalysis to chirality-dependent controllable manipulation of cell behaviours and finally to enantiopure nanoplatforms for improved disease therapy. We also discuss the current challenges and future potential of these chiral nanotechnologies in biomedicine and bioengineering, provide strategies to overcome these barriers and offer a future perspective.Ultraviolet B (UVB) irradiation-induced DNA damage, oxidative stress, inflammatory processes, and skin pigmentation cause pigmented spots, wrinkles, inflammation, and accelerated skin aging and cancer. Maqui berry (Aristotelia chilensis) is a natural antioxidant, anticancer, and anti-inflammatory food. We investigated the photoprotective properties of the ethyl acetate fraction of maqui berry ethanol extract (MEE) in vitro and in vivo. Spectrophotometric measurements revealed dominant extinction profile of MEE in the UVB range. MEE clearly reversed the DNA damage induced by UVB irradiation in HaCaT cells by upregulating endogenous cellular enzymatic and non-enzymatic antioxidant systems containing superoxide dismutase, catalase, and glutathione and reducing the production of nitric oxide. Moreover, MEE treatment enhanced the antioxidant ability and weakened lipid peroxidation in BALB/c mice exposed to UVB radiation. It also down-regulated interleukin (IL)-6 and tumor necrosis factor-α levels and up-regulated IL-4 levels. Moreover, MEE inhibited the UVB-triggered activation of ERK and p38 MAPK. These data suggest that MEE is an effective agent against UVB-induced photodamage.Operando synchrotron infrared microspectroscopy (OIMS) was used to study the conversion of methanol over coffin-shaped HZSM-5 crystals of different sizes large (?250 × 80 × 85 μm3), medium (?160 × 60 × 60 μm3) and small (?55 × 30 × 30 μm3). The induction period, for direct alkene formation by deprotonation of surface methoxy groups, was found to decrease with decreasing crystal size and with increasing reaction temperature. Experiments with a continuous flow of dimethylether showed that evolution of the hydrocarbon pool and indirect alkene formation is also strongly dependent on crystal size. These measurements suggest that the hydrocarbon pool formation and indirect alkene generation should be almost instantaneous at reaction temperatures used in practical catalysis with crystal sizes typically ?1 μm3.Necroptosis is regarded as a new paradigm of cell death that plays a key role in the liver damage observed with selenium (Se) deficiency. Se deficiency has a significant impact on the livestock and poultry industries. Previous studies have confirmed that Se deficiency causes serious injury to the swine liver; however, it is unclear whether this liver damage is the result of necroptosis and apoptosis. To understand the damage induced by Se deficiency, swine were divided into a control group and Se-deficient group. The results showed that in the liver of swine, Se deficiency initiated apoptosis by increasing the expression of cysteinyl aspartate specific proteinase 3 (caspase-3), cysteinyl aspartate specific proteinase 9 (caspase-9) and BCL-2 antagonist/killer (BAK) at both the mRNA and protein levels and by decreasing the B cell lymphoma/leukemia 2 (BCL-2) levels compared with the levels in the control group. Meanwhile, compared with the control group, necroptosis was confirmed in the liver of Se-deficient swine through increased the expression of mixed lineage kinase domain like pseudokinase (MLKL) and receptor interacting serine/threonine kinase 1 (RIPK1) at both the mRNA and protein levels. In addition, the activities of catalase (CAT), nitric oxide (NO), and total antioxidative capacity (T-AOC) were clearly increased (P less then 0.05), and the activities of OH- and total nitric oxide synthase (TNOS) were obviously decreased (P less then 0.05), whereas in the Se-deficient group, the hydrogen peroxide (H2O2) and malondialdehyde (MDA) levels were obviously increased (P less then 0.05) compared with those in the control group. Moreover, the number of apoptotic cells was increased significantly in the Se-deficient group, and the liver tissues showed obvious necroptosis damage. https://www.selleckchem.com/products/BMS-754807.html These results show that Se deficiency induces apoptosis and necroptosis through the oxidative stress pathway in the swine liver.